The ECHO phase III trial evaluated acalabrutinib + bendamustine-rituximab (BR) vs placebo plus BR in untreated mantle cell lymphoma (MCL) patients ineligible for transplant, showing a significant improvement in progression-free survival (PFS) (66.4 vs 49.6 months) with a hazard ratio (HR) of 0.73. The combination achieved a higher overall response rate (ORR) (91.0% vs 88.0%) and complete response (CR) rate (66.6% vs 53.5%), supporting its efficacy in this older population. Of note, side effects like pneumonia, atrial fibrillation, and infections were more frequent with acalabrutinib, with serious adverse effects in 69% versus 62% for placebo. This triplet regimen could redefine first-line treatment for our MCL patients, but we’ll need to stay vigilant about managing toxicities, especially in older patients.
The combination of the Bruton tyrosine kinase inhibitor ibrutinib with bendamustine-rituximab for first-line treatment of mantle cell lymphoma (MCL) prolonged progression-free survival (PFS), but without improvement in overall survival (OS), likely because of toxicity. Acalabrutinib was shown to be efficacious and less toxic than ibrutinib in a head-to-head trial in chronic lymphocytic leukemia and therefore might lead to better outcomes in MCL.
Patients 65 years and older with previously untreated MCL received acalabrutinib (100 mg twice daily) or placebo (until disease progression or unacceptable toxicity), plus six cycles of bendamustine (90 mg/m2 once daily; days 1 and 2) and rituximab (375 mg/m2 as a single dose; day 1) followed by rituximab maintenance in responding patients for 2 years. Crossover to acalabrutinib at disease progression was permitted. The primary end point was PFS per the independent review committee; overall response rate and OS were secondary end points.
In total, 598 patients were randomly assigned, with 299 in each arm. At a median follow-up of 49.8 months using the reverse Kaplan-Meier method, the median PFS was 66.4 months in the acalabrutinib arm and 49.6 months in the placebo arm (hazard ratio [HR], 0.73 [95% CI, 0.57 to 0.94]; P = .0160). Benefit was seen across all subgroups, including those with high-risk features. Overall response/complete response rates were 91.0%/66.6% and 88.0%/53.5% in the acalabrutinib and placebo arms, respectively. OS was not significantly different (HR, 0.86 [95% CI, 0.65 to 1.13]; P = .27). Grade 3 or greater adverse events were reported in 88.9% and 88.2% in the acalabrutinib and placebo arms, respectively.
The combination of acalabrutinib with bendamustine-rituximab significantly improved PFS. Clinical benefit of acalabrutinib with bendamustine-rituximab was achieved with manageable toxicity.
The BOVen regimen of Zanubrutinib, Obinutuzumab and Venetoclax showed impressive results in the TP53+ population, albeit in a small sample size here. This is on NCCN and could be considered the right patient.
For transplant-eligible patients with Mantle Cell Lymphoma, Obinutuzumab showed superior efficacy compared to Rituximab. These patients are uncommon, but the results of this study show that in this context O seems to beat R in every aspect, including a 5-yr PFS of 82.8 vs 66.6%, which is striking. I would consider this option for the appropriate patient.
Potentially practice changing trial from the EU on young, transplant eligible patients with MCL were all treated with first line chemo then randomized to Auto-HSCT +/- Ibrutinib. The addition of Ibrutinib to Auto-HSCT improved DFS compared to Auto-HSCT alone, and more interestingly patients treated Ibrutinib was better than those who had transplant but the data on the Ibrutinib vs traplant + Ibrutinib arms are premature. The addition of maintenance Rituximab did not seem to change any outcomes.
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